Optical String Tuner Known as Stimmopped

Overview

The Stimmopped project is built around an ATmega8 microcontroller creating tool that can assist in tuning any string instrument to a given tone.

Details

To give feedback about the adjustment of an instrument, this toll uses the stroboscopic effect as it contains two aligned LEDs on the board that blink with the frequency that the string has to be tuned. Two lines are projected at a fixed position on the string when the string vibrates with the correct frequency. The lines appear to be blinking or moving to the observer’s eye if frequencies don’t match. With the decreasing difference between the two frequencies, the moving or blinking effect decreases. To tune the string frequency until lines appear to be at fixed position on the string is the purpose of the whole process. Along with ATmega8 microcontroller are a couple of buttons, two LEDs, and 7-segment indicator.

To choose the tone and instrument, two switches are used by the Stimmopped. The current mode of the menu is toggled using switch S1 while the current selection is shown by the 7-segment display. the display is lit up a bit brighter in the instrument selection mode.